This invention relates to an elastic doll head formed by blow molding, a method for molding the same and a mold therefore.
Conventionally, a head for a doll or a doll head which exhibits elasticity has been generally formed of molten vinyl chloride by slush molding or rotational molding. Both slush molding and rotational molding prevent formation of such a parting line as seen in a molded doll head made by blow molding, to thereby provide a molded article or doll satisfactorily finished. Also, rotational molding leads to mass production of the doll heads at a reduced manufacturing cost.
Vinyl chloride contains chlorine and the above-described molding techniques require to add phthalate ester acting as a plasticizer to vinyl chloride in order to provide a molded article with elasticity or resiliency. Recently, safety of vinyl chloride and phthalate ester has been considered to be problematical, thus, use of vinyl chloride tends to be avoided in various fields. This is likewise true of a doll head, thus, it is required that the head be formed of a safe molding material.
However, application of a molding material other than vinyl chloride to slush molding or rotational molding is substantially impossible because the material fails to be gelled. Blow molding permits the material to be molded, however, it fails to prevent formation of a parting line on a surface of a face of a doll head molded. Also, it fails to permit the molding material to be satisfactorily distributed to fine uneven parts of the doll head such as eyes, a nose, a mouth and the like, resulting in the doll head being nonuniform in thickness as a whole, as shown in FIG. 30. More particularly, the above-described uneven parts are reduced in thickness as compared with the remaining part of the doll head, to thereby tend to be transparent or readily collapsed to a degree sufficient to cause damage thereto. In manufacturing of a doll head, it is highly required to satisfactorily finish a surface of a face of the doll head, to thereby ensure increased smoothness of the surface and enhanced elaborateness of unevenness of various parts of the face, as well as uniformity in thickness of the whole doll head. Unfortunately, the conventional blow molding techniques fully fail to meet such requirements.
Also, the blow molding causes an air blowing hole to be left in the molded doll head, because it requires blowing of air into a mold during molding of the doll head. Such air blowing is typically carried out through a top of the head. Thus, in this instance, formation of a hole through the top of the head is unavoidable. Unfortunately, this causes hair embedded on a portion of the head at which the hole is formed or a portion of the head near the hole to be readily detached from the portion, for example, when it is combed.
The mold used for the molding includes a pair of split mold members, of which one has an inner surface formed to have a configuration corresponding or conforming to a face of a doll head to be molded having complicated uneven or rugged portions such as eyes, a nose, ears and the like and the other has an inner surface formed to have a configuration conforming to a smooth occiput or rear head portion of the doll head reduced in unevenness. Thus, the doll head molded is desirably dropped away from the split mold members when the mold members are separated from each other after molding of the doll head. However, actually the molded article or doll head tends to be left in the mold of a configuration conforming to the face of the doll head. The molded doll head is rapidly cooled upon separation of the mold members from each other; so that when unless attention is paid to, during the molding, a degree to which force is applied to the mold for separation of the mold members and a direction in which the force is applied, the face of the molded doll head or article is apt to be damaged, leading to a deterioration in commercial value of the article.
Further, a doll head is required to exhibit elasticity sufficient to permit the doll head to provide a soft touch like the human skin. Thus, the head must meet such a requirement as well.
The present invention has been made in order to solve the above-described problems of the prior art. Thus, it is an object of the present invention to provide an elastic doll head, a method for molding the doll head and a mold for the doll head which are capable of permitting the doll head to be formed by blow molding using a molding material other than vinyl chloride while minimizing nonuniformity in thickness thereof.
It is another object of the present invention to provide an elastic doll head, a method for molding the doll head and a mold for the doll head which are capable of permitting a hair embedding treatment to be satisfactorily carried out without leaving a parting line and/or an air injection hole on a main part of an outer surface of the doll head during molding.
It is a further object of the present invention to provide an elastic doll head, a method for molding the doll head and a mold for the doll head which are capable of permitting the doll head to be effectively detached from mold members of the mold upon separation of the mold members from each other.
In accordance with one aspect of the present invention, a method for forming an elastic doll head is provided. The method is characterized in that the method comprises the steps of: providing split mold members each having an inner surface formed to have a configuration which provides a shape of the doll head when the split mold members cooperate with each other, the split mold members forming the doll head with a parting line through which the doll head is substantially equally divided into two halves; heating a molding material mainly consisting of one selected from the group consisting of a thermoplastic synthetic resin elastomer and a silicone resin material, dropping the molding material in the form of a parison into a space defined between the split mold members kept spaced from each other, joining the split mold members to each other, and blowing air into the split mold members thus joined; and separating the split mold members from each other to remove the molded doll head from the split mold members; the split mold members each being formed with a cavity and a mating surface so that the parting line is formed on the doll head so as to extend from an upper portion of a forehead of the doll head through a rear side of each of ears thereof to a rear portion of a neck thereof; one of the split mold members being formed with a neck hole forming means in a manner to be retractably advanced into the cavity; the neck hole forming means being formed with an air injection nozzle for injecting air into the cavities of the split mold members, resulting in blow molding being carried out.
In accordance with this aspect of the present invention, a method for forming an elastic doll head is provided. The method is characterized in that the method comprises the steps of: providing split mold members each having an inner surface formed to have a configuration which provides a shape of the doll head when the split mold members cooperate with each other, the split mold members forming the doll head with a parting line through which the doll head is substantially equally divided into two halves; heating a molding material mainly consisting of one selected from the group consisting of a thermoplastic synthetic resin elastomer and a silicone resin material, dropping the molding material in the form of a parison into a space between the split mold members kept spaced from each other, joining the split mold members to each other, and blowing air into the split mold members thus joined; and separating the split mold members from each other to remove the molded doll head from the split mold members; the split mold members each being formed with a cavity and a mating surface so that the parting line has a portion associated with each of ears of the doll head in a manner to extend along an outer edge of the ear.
Also, in accordance with this aspect of the present invention, a method for forming an elastic doll head is provided. The method is characterized in that the method comprises the steps of: providing split mold members each having an inner surface formed to have a configuration which provides a shape of the doll head when the split mold members cooperate with each other, the split mold members forming the doll head with a parting line through which the doll head is substantially equally divided into two halves; heating a molding material mainly consisting of one selected from the group consisting of a thermoplastic synthetic resin elastomer and a silicone resin material, dropping the molding material in the form of a parison into a space between the split mold members kept spaced from each other, joining the split mold members to each other, and blowing air into the split mold members thus joined; and separating the split mold members from each other to remove the thus-molded doll head from the split mold members; the parison being formed to have a nonuniform thickness.
In a preferred embodiment of the present invention, the air injection nozzle forms the doll head with a hole which acts as an engagement hole through which the doll head is engaged with a doll body.
In a preferred embodiment of the present invention, the pre-blowing is carried out during the blow molding. Alternatively, a stationary pin may be arranged between the split mold members, wherein the split mold members are each formed at a portion thereof corresponding to the stationary pin with a molding space for formation of an additional increased-thickness portion, and the stationary pin is embedded in the additional increased-thickness portion which the molding space is filled with during molding of the doll head.
In a preferred embodiment of the present invention, air in the cavities of the split mold members is removed through at least one of projections provided on the doll head when air is injected into the split mold members.
In a preferred embodiment of the present invention, the split mold members are each formed of a porous metal material into a breathable structure including a number of fine pores as a whole.
In a preferred embodiment of the present invention, the parison is formed to have a nonuniform thickness. In a preferred embodiment of the present invention, the parison may be formed to have a nonuniform thickness in either cross section or vertical section. Alternatively, the parison may be formed to have a nonuniform thickness in both cross section and vertical section. In a preferred embodiment of the present invention, the parison is formed by means of a die of a nonuniform diameter.
In a preferred embodiment of the present invention, the split mold members are provided at a portion thereof corresponding to a neck of-the doll head with a rod in a manner to be retractably advanced into the cavity. The rod is advanced into the cavity after injection of air and retracted from the cavity before separation of the split mold members.
In accordance with another aspect of the present invention, an elastic doll head is provided. The elastic doll head is characterized in that the doll head is made of a molding material mainly consisting of one selected from the group consisting of a thermoplastic synthetic resin elastomer and a silicone resin material by blow molding and formed thereon with a parting line which extends from an upper portion of a forehead of the doll head through a rear side of each of ears thereof to a rear portion of a neck thereof; wherein the neck has a hole formed therein during blow molding.
In a preferred embodiment of the present invention, the hole may act as an engagement hole for engaging the doll head with a doll body therethrough.
In accordance with this aspect of the present invention, an elastic doll head is provided. The elastic doll head is characterized in that the doll head is made of a molding material mainly consisting of one selected from the group consisting of a thermoplastic synthetic resin elastomer and a silicone resin material by blow molding and formed thereon with a parting line which substantially equally divides the doll head into two halves in a longitudinal direction thereof; wherein the parting line has a portion associated with each of ears of the doll head in a manner to extend along an outer edge of the ear.
In a preferred embodiment of the present invention, the doll head is formed with a neck hole. The parting line is formed so as to extend along a lower surface of a chin of the doll head from below the outer edge of each of the ears and pass around a front portion of the neck hole. For example, the doll head may be formed to have dimensions of about 40 mm in height, about 30 mm in width and about 4 mm in length between an open end of the neck hole and a step behind the open end.
In accordance with a further aspect of the present invention, a mold for forming a molding material mainly consisting of one selected from the group consisting of a thermoplastic synthetic resin elastomer and a silicone resin material into an elastic doll head by blow molding is provided. The mold is characterized in that the mold comprises: a pair of split mold members each having an inner surface formed with a cavity and a mating surface so as to form a parting line when the split mold members cooperate with each other, the parting line being formed so as to extend from an upper portion of a forehead of the doll head through a rear side of each of ears thereof to a rear portion of a neck thereof; one of the split mold members being formed at a portion thereof corresponding to a neck of the doll head with a through-hole, the through-hole having a neck hole forming means slidably fitted therein, the neck hole forming means being provided at a distal end thereof with an air injection nozzle.
In a preferred embodiment of the present invention, the split mold members are each mounted therein with a pre-pinch member for pre-blowing. The pre-pinch member is urged in a direction in which it projects from the mating surface by means of a spring. Also, a molding space is defined between the pre-pinch member of each of the split mold members and the cavity thereof for forming an additional increased-thickness portion connected to the parting line through a reduced-thickness portion.
In a preferred embodiment of the present invention, a stationary pin is arranged between the split mold members and the split mold members are each formed at a portion corresponding to the stationary pin with a molding space for forming an additional increased-thickness portion.